Sampling sub with removable cutting collector



Uct. 14, 1952 J. N. GREGORY 2,613,916

SAMPLING SUB WITH REMOVABLE CUTTING COLLECTOR Filed Oct. 31, 1950 O 2SHEETS-SHEET l FIG. 6

lnven+0r= Jo mes N Gregor BLT MW Oct. 14, 1952 J. N. GREGORY SAMPLINGSUB WITH REMOVABLE CUTTING COLLECTOR 2 SHEETSSHEET 2 Filed Oct. 31 1950FIG. 8

FIG]

James N. Gregory \nver'd'or:

His Afiornem,

Patented Oct. 14, 1952 SAMPLING SUB WITH REMOVABLE "CUTTING COLLECTOR.James .N. Gregory, Fullerton, .CalifQ, .assignor to zShell .DevelopmentCompany, San Francisco, -Ca-lif,, azcorpor-ation of Delaware'AppIication'October 31, 1950, Serial No. 193,189

The present invention relates to apparatus for drilling and coring orlogging wells and pertains more particularly to apparatus for collecting:samples of iormation cuttings from -a stream of drilling fluid at apoint near a drill bit during rotary-drilling.

During well drilling operations, -a well may be logged by studying theearth cuttings as they return to the-top of the well in the circulatingstream of drilling fiuid. Thefluid is either run through a screen uponwhich the cuttings are .collected,:or a sample of fluid -is periodicallytaken from the .drilling fiuid stream, ditch-or pit, and .the cuttingscontained therein are later separated from the fluid in a laboratory.The main disadvantages of collecting samples of 'bit cuttings at the topof the well is that the'cuttings are gen- --erally *small in 'size and'have been contaminated by being carried in the stream 'of drillingfluid for as long as an hour or more. Itis furthermore difficult tocorrelate the cuttings with the *par- 'ticular depths to which theybelong.

"Thus, in order to obtain "relatively large, -un- "contaminated samplesof the formation being traversed by a borehole, it is generallynecessary 11 Claims. (Cl. 255-i1.'.4)

to resort to -bottomhole or side-wall coring.

These methods of "coring, while normally ade- -quate, result inconsiderable loss of "time in that drilling operations must be stoppedwhile a core :is taken. "-tainedby conventional apparatus are "ofteninadequate *for *m'icrofaunal determination because microfauna specimensoccur -instreaks which are oftenmissedby taking spot core samples.

Samp'ling 'devices for obtaining bit cuttings from the bottom of aborehole usually have the drawback of being fixedly secured 'to thelower portion of a drill string, necessitating theshut- -ting down 0fdrilling operations and the raising [of the entire can string to thesurface for the removal of the cuttings' from the=samp1ing device. -Itis therefore a primary ob-ject of the present invention to provideapparatus for continuously obtaining samples dfrelattvely'large size'bit cuttings from 'ithe circulating drilling fluid.

'It' is also an object-of this invention-'to -pro vide apparatus forcontinuously obtaining uncontaminated samples of earth -or "cuttingsnear the ibottom of 'a borehole directly after they :are iwashedawayfrom thedrillbit.

.Ano'ther:obj ect: of .this invention -is to provide n novel type ofsampling sub :adapted to contain-a :sampling :device :for :continuouslyareceiving bit -r cuttings, said ssub being .:provided :with :conduitAdditionally, -sidewall samples 'ob- .2 thereth-rough while samplecuttings :are being obtained.

-I hese and other objects .of this invention will be understood from thefollowing description 10f the invention as shown in the accompanyingdrawing, wherein:

Figures ,1 to 4 are views, partly-in crosssection. of di'fierentembodiments of the present appa- -ratus, .comprising a'sampling devicepositioned in a specialrsubor section of a drill string.

Figure 5 'isa cross-sectional view taken along the line v5':5 :ofFigure,1.

Figure 6 is a cross-sectional view taken along the line 6'6 of Figure 3.

Figure 7215 a viewinfront elevation cf'a closure sleeve or :plug adaptedto be lowered into the special :sub :in place of a sampling device.

1Figure.8 is :an isometric view of a removable liner-adapted to fitwithin the chamber of .a;:sampling-device.

Figure 9 is a view, taken in cross section, illustrating the presentsampling device and :its :associated sub positioned in a drill string at:the :bottom of a well .borehole.

Referringto Figure 1 ofthe-drawing,vthe;present sampling apparatuscomprises :an elongated tubular member i=0 having fixedly positioned :inits bore ill suitablecontainer :means such ;as ;a holder l2 .forpositioning a sampling device :or cutting collector t3 therein. Thetubular "member 1-0, otherwise known as asub orshortsection of :drillpipe or :drill collar, .is threadedzatzits upper :and lower ends 14 and15, respectively, :whereby theupper end :l ll maybe connected to.a'section of drill pipe or a drill collar I6, and the lower end 15 maybe connected to another ,section 'of the drill pipe or to a bit H. Thespecialf sub 10 :is preferably .zconnected into :the drill string l6directly above a wall scraper or drill bit 1|:1, :as

shown in Figure 39, but it is understood that the present sub may beconnected between .any two sections of theydrill string.

The tubular smember I0 is provided with :one or more slots'or ports I 8through the wall l9 thereof to permit earth. cuttings .to enter .thebore :11. Preferably, the axis 'of the slot l8 slants downwardly-to:permit any cuttings :entering :the .SlOt l8 to slide-into "the bore 1I. Howeven-the ".walls .of the 'slot may have any other slant :(or mayextend horizontally, .as shown :in Figure '19-) Preferably, the slot [8is located near :the upper zend ofthe sub 5E0 and-may be :of any sizedesired. However, 'the' slot opening shouldihave :an area :of :severaltimes :the size of the cuttings which iit Iimam for permitting 1131 8;jfl .;of .drilling zflui'diifib is .idesired-rto- 'collec't. :If:desired, ,an annularrecess 20, having a width at least equal to thelength of the slot I8, may be cut in the outerwall of the tubular memberII! at the level of the port or ports I8. The purpose of this annulargroove or recess 20 will be explained hereinafter.

The axial bore II of the sub I is normally of the'same diameter as thebore of the drill string I6. The holder I2, which may be formed of atubular member open at its upper end 2| and preferably closed at itslower end 22, is fixedly supported in a preferably coaxialmanner in thebore I I of the sub II] by support members 23 and 24, seen in Figure 1,or 25 and 26, seen in Figure 5. The holder I2 is provided near its upperend with a longitudinal slot or Window 2! through the wall thereof, saidslot 21 being preferably equal in size to the slot I8 in the sub 16, topermit earth cuttings to pass readily therethrough and into a containerI3 carried within the holder [2. The supports 23,

' 24, 25 and 26, which may be Welded to both the inner wall of the subI6 and the outer wall of the holder I2, form a short conduit orfluidtight passage for conducting samples entering the slot I8 in thesub across the annular space between the sub I0 and the holder I2 andthrough the slot 21 therein. If desired, the supports 23 to 26 and theedges of the slot 21 in the holder I2 may be slanted at substantiallythe same angle as the walls of slot [6 to facilitate the entranceofcuttings into the collector I3.

Preferably, a small port 29 is drilled in the wall of the sub II] at alevel below the lower end of the holder I2. A similar port 36 isprovided in the lower end of the holder I2 and a short section ofconduit 3| is inserted through said ports 29 and 36 and welded thereinso that the bore 32 of the holder is in communication with the spaceoutside of the sub Ill. The conduit 3I is preferably slanted to permitcuttings or debris, which may enter the scabbard I2 when the collectorI3 is removed, to drain therefrom.

The sampling device or cutting collector I3 comprises an elongatedtubular member closed .at both ends to form a chamber 39, the lower endthereof being closed preferably by a removable pointed cap 33. Theremovable cap 33 facilitates the removal of cuttings from the collectorand its pointed shape serves as centering or guide means when'thecollector I3 is dropped into the holder I2. The upper end of thecollector I3 is provided with an enlarged shoulder 34 which is adaptedto be seated on the upper edge 35 of the tubular holder I2, as shown inFigure 1, thus supporting the collector within the holder. The collectorI3 is provided with one .or more windows 36, 3'! and 38 which are ofsuch dimensions and are so disposed in the wall of the collector that atleast one of them is always in register with the slot 2'! inholder I2,whereby earth cuttings may pass through said slot and windows into thechamber 39.

In order to secure a more fluidtight seal between the cutting collectorI3 and the inner wall of the holder I2, one or more annular grooves maybe cut or formed in the outer surface of the collector I3 to accommodaterings 40 of any suitable packing material. Generally, however, anadequate seal is provided at the point where the shoulder 34 contactsthe beveled seat 35.

The top III of the cutting collector is provided with anupwardly-extending axial rod 42 on which is mounted a centralizer of anydesired type. As illustrated here, the centralizer comprises a pair ofstop rings 43 and 44 fixedly secured to the rod 42, a pair of collars 45and 46 slidably mounted on said rod 42 outside of said stop rings and aplurality of leaf springs 4! and 48 tending to expand and therebymaintained in sliding contact with the inner wall of the drill stringIS. The upper end of the rod 42 is provided with a fishing neck 49 forremoving the cutting collector I3 from the scabbard I2 and drill stringI6.

In another embodiment of the present invention (Figure 2), a sub 56having a sampling window 5I through the wall thereof is provided with aholder 52 eccentrically and slantingly mounted within the bore 53 ofsaid sub 50. The holder 52 is also provided with a window 54 in the wallthereof which is in register with the Window 5| of the sub 56 when theholder 52 is affixed, as by welding, to the inner wall of the sub 50.The lower end 55 of the holder 52 is closed to form support means for asample collector 56 adapted to be contained within the holder. A drainport 5! is drilled in one side of the holder 52 near the bottom thereofso as to register with a drain port 56 in the wall of the sub 56. Thelower end of the holder 52 is preferably welded to the sub 56 at thedrain port 58.

In order fora cutting collector 56 to enter the holder 52 when saidcollector is dropped down through the drill string I6, it is essentialthat the holder be of sufficient diameter, or be so positioned in thebore of the sub 56, that at least a portion of the open upper end 59 ofthe holder intercepts the axis of the subbore 53. Thus, with thecollector 56 provided with a pointed cap 60 on its lower end andcentralizer springs 6| and 62 near its upper end, the collector will beguided into the open end 59 of the holder and will drop into position inthe holder as illustrated in Figure 2. Preferably, the bore 53 of thesub 56 is enlarged below the Window 5| in the sub, as shown at 63,whereby the holder 52 may be fixedly secured to the inner wall of thesub 56 in a tilted position which positions the upper end of the holdersubstantially in the center of the sub.

Threadedly secured to the top of the collector 56 is a rod member 64carrying the centralizer springs BI and 62 which may be designed to fitwithin the holder 52, and rings 65 of suitable packing material forforming a fluidtight seal between the collector 56 and the holder 52.While it is not essential that the collector and the holder be influidtight engagement, sealing means are preferably employed to preventany of the drilling fluid flowing down the pipe string l6 from enteringthe space between the collector 56 and the holder 52 and thus possiblydisturbing the flow of cuttings entering windows 5i and 54. The top ofthe rod member 64 is also provided with a fishing neck 66 similar to theone in the embodiment of Figure 1. l a

In the embodiment illustratedin Figures 3 and 6, a sub 10 is providedwith a pair of diametrically positioned windows or slots II and 12through the wall thereof. A holder I3 is axially mounted in the bore I4of the sub In, said bore I4 being enlarged over the portion of the subadjacent the holder 13 to providean enlarged annular flow passage forfluid as it flows by the holder. The tubular holder I3 is provided witha pair of diametrically opposing slots 15 and 16 which communicate withthe windows II and 12 in the sub 1.6 by a pair of slanting flowout theslots I5 and I6.

TI and I9 are positioned between and engage I plates8I and 83, whilesupportplates I8 and 80 enga e plates 82 and 84. The members 11 to 84are welded to the inside wall of the sub I and the outside wall of theholder 13 to form. 1

support means for positioning theholder in the center of the sub.v

The .holder I3 is open at both ends, the upper end 85sbeing beveled toseat the shoulder. 86 of a cutting collector 81 while the lowerend 88 isopen to allow any material collecting therein to. be dischargedtherefrom. When employing a. holder I3 having its lower end open, itmaybe. found .desirable to equip the collector 81 with packing rings 89below its sample receiving slots 90.and 9I' as well as packing rings .92above said slots thereby preventing any flow of fluid up the holder andout .its windows I and I6.

In; another embodiment of. the present invention, shown in Figure 4, asub I00, having a single window IOI through the wall thereof, maycontaina holder I02 having one window I03 and adapted to receive a.cutting collector I04. The Scabbard I02 may be welded to spacer blocksI05, I06 and N1 which are in. turnwelde'dto the inner surface of. thesub I00.

When a cutting collector I04 is provided with a single window I08, it:is necessary to provide.

projects horizontally a short distance into the bore II thereof. As thecollector I04 is lowered into thesubbody I00, the projecting pin II2will rideuup the shoulder H0 and cause the col- 1ecto'r'I04 to rotateinvthe bore of the sub I00 until: the-pin I12 and slot I09 are. invertical alignment. In this position thewindows IN and I08 in thesub.I00 and collector? I04, respectively, are: in. register. 3

During drilling operations when no sampling off cuttings is desired, acutting collector, such for example, as 81 (Fig. 3), may be removed andreplaced with a suitable'plug or closure means for closing the slots I5and 18 inthe holder whereby a drilling fluid being circulated downthe'drillstring I6 will not by-pass the bit and As shown in Figure 7,one embodiment of a slot closure means may comprise a tubular member orclosure sleeve H5 which'is equipped with a seating shoulder II-S nearthe upper end thereof which is adapted to engage the shoulder 85 at thetop of the holder I3. The length of the tubular member 5' is such thatthe bottom of said member extends below the slots I5 and 1B, effectivelyclosing them. The upper end of theclosure sleeve,

30 in the cutting collector I3, maybe, closed bya removable plug 33which is secured ineany suit.-

able manner, as in screw-threaded engagement,-

tofthe bottom-of the collector I3. Ely-removing theplug 33, thecollected-cuttings may-be readily removed from the chamber 39. If;desired, the collector may be equipped with a removable liner I20(Figure 8), having an open top and a closed lower end; The linerjisformed of a thin material shaped. to fit within the annular chamber 39.Whilea thinmetallic liner I20 may be used,

' it=is preferably made of a transparent. plastic cuttings in the'linerI will be arranged in. the

'lector '13, by a inverse order in which the strata are penetrated. Thecutting collector is :loweredbyc'able .or

dropped through the drill string i 6. and, into position-in the sub I0,as shownsin Figure a If: acable I2'3 is employed to .lowerthe'co-ll'ector, the cable is withdrawn tothe surface beforedrillingoperations are resumed. Drilling fluid being circulated-down thedrill string; Ifiepasses through-the annular space II around theholderI2, through the bit I1, and up the annular 'pase sageway-I2'4 betweenthe drill t6 and. the

wall or theborehole. ,1

The present cutting collector operates on the "principle that thevelocity of .thetcirculating fluid rising in the annular passageway.I'21I..is reduced wh'enfthe fluid passes the slot; I8 and window 21- inthe sub-I0 and the sample collector, respectively; An annular. recess 20'. v(Figure 1) in the outer wall of the sub 1 01 also acts to reducethevelocity-ofthe-fiuid flow," The. re.-'

sulting decrease in the circulating. fluid velo'city' together withtheturbulence created by the slots reducesthe carrying power ofthecirculating fluid; The earth cuttings, especially thesl'arger and moredesirable ones, are thrown Jouto'fethe mud stream and into 'thechamberr39- of: the collector I3. Thecollected cuttings may beiraisedtothe surface of -the well along with the colfishing tool I22 atthetendofra cable I23.

I claim as -my invention:

1. Apparatus for collecting earth cuttings; from mudflush circulating ina borehole, comprising in combination a. tubular: member adapted to beconnected into a drill string, a tubularholder fixedly carried withinthe: bore vofi said tubular member co-longitudi'nally therewith, the:outer -"diamet'eri ofsaid holder being appreciably smaller walls of saidtubular member and said tubular holder adapted to register with saidwindow means when said collector is insertedin. said holder, and fishinghead means affixed' to the upper part of said collector for raisingsaid? collector -fromsaid holder.

thereto by a. plurality of spaced lugs II8. Suit-- able centralizingsprings I2I are also secured to-theupper end of the sleeve II5.

It 'is' realized that various changes and modiflcations may be made inthe elements described herein without departing from the principles ofthis-inventioni As described with regard to the embodimentillustrated inFigure 1, the chamber 2. Apparatus for collecting earth cuttings frommudflush circulating in a borehole, comprising in combination a tubularmember adapted to be connected into a drill string, a tubular holderopen at. its upper end and closed at'its lower end positioned within thebore of said tubular member coaxially therewith, the outer diameter of'said'holder being appreciably smaller than the innerdiameter of saidbore, whereby an annular fluid passage is formed'within said bor'e aboutsaid holder, spider means in said passage fixedly attaching said holderto said member, conduit means through' the-wall of said tubularmemherand through the wall of said tubular holder near the lower endthereof,.a hollow cylindrical sample collector slidably fitting withintheholder, radial windows through the: walls of said;:.col- 'lector nearthe upper end thereof, "ported radial conduit meansithrough'the walls.dfzsaid tubular member and said tubular holder adapted. to register withsaid windows when said. collector is inserted in said holder, andfishing head means afiixed .to the upper part of said collector forraising said collectorfrom saidholder. 1

3. Apparatus for collecting earth cuttings. from mudflush, circulatingin :a borehole, comprising in combination a tubular-member adapted to beconnected into a drill string, atubular holder fixedly carriedeccentrically within the bore of said tubular member co-longitudinallytherewith,

the axis of the bore of said tubularmemberbeing arranged at an angle,inclined ,to -.the axis ofcthe bore of said tubular; holder, the outer Idiameter of said holder. being considerably smaller than the innerdiameter,.ofsaidcbore, whereby a fluid passage is formed within said Ibore outside said holder, a hollow cylindrical sample collector slidablyfitting within the holder,

. radial window means throu h the walls of said collector, a portedradial conduitthrough the walls of said tubular, member and saidtubular,

holder adapted to register with said window means when said collectoris" insertedinsaid holder, and fishing head means 'afiiXed to the upperpart of said collector for-raising said'collector from said holder. 1 ah 1 4. Apparatus for collecting earth ,cuttingsfrorn mudflushcirculating in a borehole, comprising in combination a tubular memberadapted :to be connected into a drill string, a tubularholder fixedlycarried eccentricallyand slantingly within the bore of said tubularmember,- substantially co-longitudinally therewith in a manner suchthatthe axis of the bore of said tubular member passes within the peripheryof .the upper open endof the bore of saidho-lder, said holder beingclosed at the lower end thereof, the outer diameter of said holder beingappreciably smaller than the inner diameter of said bore, whereby afluid passage is formed within said bore outside said holder, a hollowcylindrical sample collector slidably fitting within-the holder, saidcollector having a tapered lower end for guiding said collector intosaid holder, radial win- .dow means through the walls of said collector,

a ported radial conduit through the walls of said tubular member andsaid tubular holder adapted to register with said window means-when saidcollector is inserted in said holder; a ported drain conduit extendingoutwardly through the wall of said tubular member and inwardly throughthe wall of said holder in communication with the closed lowerendthereof, and fishing head means afiixed to the upper part ofsaidcollector for raising said collector from said holder. 7 w I 1 5,Apparatus for. collectingearth cuttings from mudfiush circulating'in aborehole, comprising in combination a tubularmember adapted to beconnected into a drill string, a tubular holder having an open upper endfixedlycarried within the bore of said'tubular member co -longitudinallytherewith, thev outer diameter of saidholder window when said collectoris inserted :in .saidholder, fishing head means affixed to the upperpart of said collector for raising said collector from said holder, "andregistering first and second guide-*means respectively carried by-saidholder and said collector, whereby the engagement of said firstand-second guide meansupon the downward sliding of said collector withinthe bore of saidtubular holder moves said collector to a positionwherein the'window thereof registers with thelported conduit throughsaid tubular member and holder. l 1- 6. Apparatus for collecting earthcuttingsfrom mudfiush circulating in a borehole,comprising incombination a tubular member'adapted to be connected into a drillstring, a tubularholder fixedly carried within the bore of said tubularmember co-longitudinallyv therewith, the outer diameter of said :h'olderbeing 'lc'ons'iderably smaller than the inner,..diam'eter of said'bore,whereby a fluidpassage-is formedunwithini said bore about said holder, ahollow cylindricalisample collector slidably fitting within the holder,

a' radial window through the walls of 'said'collector, a ported radialconduit through the walls of said tubular member and said tubular holderadaptedto register with said:window whensaid collector is inserted insaid holdenifishing head means affixed to the upper part'of saidcollector forraising said collector from said holder? and registeringpin and guide means, one ofsaid means carried by said'collector and theother by saidholder, whereby the engagement :of said guide means withsaid pin means 'upon theentry ofsaid collector intolthe bore ofwthetubular holder causes said collector to rotate until the window thereofis in register withusaid' ported radial conduit through thetubular'member. and holder as the collector i'sloweredlinto the holder.

7. Apparatus for collecting earth cuttings from mudfiush circulating ina boreholaycomprising in combination a tubular member adapted to beconnecteduinto a drill string, a tubular holder fixedly carried withinthe. bore of, said tubular member co-longitudinally therewith, the outerdiameter of said; holder being considerably smaller than the innerdiameter of said bore, whereby, a fluid passage is formedwithin-saidbore about said holder, a'hollow cylindrical sam ple collector slidablyfitting within the holder, radial window means through the walls of saidcllector, ported radialconduit means through the walls of said tubularmember and said tubular holder adapted to register with said windowmeans when said collector is inserted in said holdenthe outer wall of;said tubular member having an armular recess formed therein at the levelof the ported'radial conduit means, and fishing head means afiixed tothe upper part of said collector, for raising said collector from saidholder. I I w 8. Apparatus for collecting earth cuttings from mudflushcirculating in a borehole, comprising open upper end, spider meansfixedly supporting said holder member within said enlarged bore portion,an annular fluid passage being formed within said enlarged bore portionabout said holder, a hollow cylindrical sample collector slidablyfitting into the holder, radial windows through the walls of saidcollector, ported radial conduit means through the walls of said tubularmember and said tubular holder adapted to register with said Windowswhen said collector is inserted in said holder, and fishing neck meansaffixed to the upper part of said collector for raising said collectorfrom said holder.

9. Apparatus for collecting earth cuttings from mudfiush circulating ina borehole, comprising in combination a tubular member adapted to beconnected into a drill string, tubular holder means fixedly positionedwithin the bore of the tubular member, said holder means being open atthe upper end and having an outside diameter substantially smaller thanthat of the bore of said tubular member, whereby a flow passage isformed between the outer wall of said holder means and the wall of saidbore, drain means in the lower end of said holder means, conduit meansthrough the walls of said tubular member and said holder means invcommunication between the bore of said holder means and the spaceoutside said tubular means, an elongated hollow cylindrical samplecollector fitting slidably within the holder means for insertion andremoval through the upper open end thereof, an axially-elongated chamberin said sample collector closed to the space within said drill string,radial window means opening to said chamber through the walls of saidsample collector, said window means being adapted to register with theconduit means of said tubular member and holder means when said samplecollector is placed therein, and centralizer means carried by saidsample collector for centering said sample collector as it passesdownwardly through the drill string,

10. Apparatus for collecting earth cuttings from mudfiush circulating ina borehole, comprising in combination a tubular member adapted to beconnected into a drill string, a tubular hold-' er fixedly positionedwithin the bore of the tubular member, said holder being open at itsupper end and having an outside diameter appreciably smaller than thebore of said tubular member whereby a flow passage is formed between theouter wall of said holder and the wall of said bore, drain means in thelower end of said holder, conduit means through the walls of saidtubular member and said holder, an elongated hollow cylindrical samplecollector fitting slidably within the holder for insertion and removalthrough the upper open end thereof, said collector having a taperedlower end, shoulder means formed on the outer wall of said collectornear the upper end thereof arranged to seat on the upper end of saidholder, an axially-elongated chamber in said sample collector closed tothe space within said drill string, radial window means opening to saidchamber through the walls of said sample collector, said window meansbeing adapted toregister with the conduit means of said tubular memberand container means when said sample collector is supported therein, andcentralizer means carried by said samplecollector for centering saidsample collector as it passes downwardly through the drill string.

11. Apparatus for collecting earth cuttings from mudfiush circulating ina borehole, comprising in combination a tubular member adapted to beconnected into a drill string, a tubularholder fixedly positioned withinthe bore of the tubular member, said holder being open at its upper endand having an outside diameter substantially smaller than the bore ofsaid tubular member whereby a flow passage is formed between the outerwall of said holder and the inner wall of said member, drain means inthe lower end of said holder, conduit means through the walls of saidtubular member and said holder, an elongated hollow cylindrical samplecollector fitting slidably within the holder for upward removaltherefrom, said collector having a removable tapered lower end, shouldermeans ,formed on the outer wall of said collector arranged to contactthe upper end of said holder'for supporting the collector therein, anaxially-elongated'chamber in said sample collector closed to the spacewithin said drill string, radial window means opening to said chamberthrough the walls of said sample collector, said window means beingadapted to register with the conduit means of said tubular member andcontainer means when said sample collector is supported therein, aremovable open-top liner carried within said chamber below said windowmeans, and centralizer means carried by said sample collector forcoaxially centering said sample collector as it passes downwardlythrough the drill string.

JAMES N. GREGORY.

REFERENCES CITED UNITED STATES PATENTS Name Date Sewell Oct. 19, 1943Number

